You can do multitrack recording using a program called Audacity, its mac and pc compatible and a pretty decent. Best of all is the price.. FREEEE!
Short of spending loads of cash and learing a ultra complicated program, it is the best i have used.

You'd get a far better experience if you got your hands on a copy of Adobe Audition - which has the same inline editor capabilities as Audacity, but is far more flexible, doesn't have the world's most retarded UI (how are people these days still writing programs that don't prompt you to save a file when you're closing it?), doesn't crash whenever you try to do anything mildly strenuous and generally is a lot more flexible.

Don't tell anyone I told you this, it's between me and you right? Choose which program you want, then steal it from the internet. I'd recommend www.scrapetorrent.com as a place to start. It's fine, coz the sex pistols used to nick instruments and that, this is the twentieth century version of that. Sort of.

I did this for a while. Then when I started using the software a lot it would crash quite often and start losing my project files. And you can't ask the manufacturers for updates or to fix it for you. Don't worry, I ain't getting on my high-horse - high-end music software is ridiculously overpriced, and I would even recommend having a trial run of a piece of software before taking the plunge (if you want).

Then I went an bought the software I needed, and for half price as an educational discount (just had to send a photocopy of my student card). And now I can get support when I need it, but hopefully won't as it's a much more stable option, apparently. Only time will tell.

Although (as any avid Sound On Sound reader will tell you) you can get just as good results from a copy of Reaper (£30) and a shitload of free VSTs then you can from a copy of Cubase (£600), Logic (£300), ProTools (£150) and a load of Waves Plugins (£500 upwards), as long as you know what to do. Hey, you might even learn more along the way.